Les 16-Configure Cluster

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Copyright 2009, Oracle. All rights reserved.

Configuring a Cluster


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Copyright 2009, Oracle. All rights reserved.1 6 - 3

Road Map

Preparing for a cluster

Cluster architecture

Network and security topology

Machines

Names and addresses

Configuring a cluster


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Preparing Your Environment

Before you configure a cluster, you need to prepare your

environment.

Determine your cluster architecture.

Understand your network and security topologies.

Choose the machines for the cluster installation.

Identify IP addresses or DNS names, and port numbers for

the server instances in the cluster.

For proxy architectures, you could have:

A single firewall between untrusted clients and the Webserver layer

A firewall between the proxy layer and the cluster

Configure the Node Manager


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Hardware

You can set up a cluster on a single computer for

demonstration or development.

This is not practical for production environments.

Each computer involved in a cluster should have a static IP

address. There is no built-in limit for the number of server instances

in a cluster.

Large multiprocessor servers can host clusters with

numerous servers.

The recommendation is one server instance for every twoCPUs.


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IP Addresses and Host Names

The IP address and host name information is needed for

configuring and managing:

The administration server

Managed servers

Multicast communication For a production environment, use the host name resolved

at DNS rather than IP addresses.

Firewalls can cause IP address translation errors.

Each server should have a unique name.

The multicast address should not be used for anything

other than cluster communications.


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Cluster Address

The cluster address is used to communicate with entity

and session beans by constructing the host name portion

of the request URLs.

You can explicitly define the address of a cluster.

The cluster address should be a DNS name that maps to theIP addresses or DNS names of each Oracle WebLogic

Server instance in the cluster.

You can also have Oracle WebLogic Server dynamically

generate an address for each new request.

Minimizes configuration Ensures an accurate cluster address

The dynamic cluster address is created in the form of:

listenaddress1:listenport1,listenaddress2:liste

nport2,listenaddress3:listenport3


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Road Map

Preparing for a cluster

Configuring a cluster

Administration Console

Configuration Wizard

WLST

Ant


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Methods of Configuring Clusters

There are multiple ways to create and configure an Oracle

WebLogic Server cluster:

Configuration Wizard


WebLogic Scripting Tool (WLST)

Java Management Extensions (JMX)

WebLogic Server API


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Copyright 2009, Oracle. All rights reserved.16 - 10

Creating a Clusterby Using the


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2


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Setting Cluster Attributes


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Configuring Cluster Communication

Number of missed heartbeatsbefore failure is assumed

For Multicast: Number of network

hops (subnets) that a message is

allowed to travel


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Adding Cluster Members: Option 1

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Adding Cluster Members: Option 2

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3


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Creating a Cluster with the Configuration Wizard


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Clusters and the Configuration Wizard


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Clusters and WLST

connect('myuser','mypass','myhost:7001')

edit()

startEdit()

cd('/')

cmo.createCluster('HRWebCluster')

cd('/Clusters/HRWebCluster')cluster = getMBean('/Clusters/HRWebCluster')

cd('/Servers/serverA')

cmo.setCluster(cluster)

cd('/Servers/serverB')


cd('/Servers/serverC')


activate()

disconnect()

exit()

Create a new

cluster.

Assign cluster members.


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Creating a Cluster Using the Cluster MBean

The Cluster MBean is used to create a cluster by using Ant

or command-line tools.

Configuring the cluster from the command line requires the

combined use of Cluster and Server MBeans.

To create new clusters within a domain, use: weblogic.management.configuration.ClusterMBean


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Synchronization When Starting Servers in a

Cluster


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ConfiguringOHS as ProxyServer

To effectively use the load balancing and failover features,

you should configure a proxy.

You can configure OHS as the proxy by:

Including configuration directives in httpd.conf

Creating another file with directives and setting an includedirective in httpd.conf

The WebLogicCluster directive is the most importantmod_wl_ohs for a cluster.

You specify the list of host names of the managed servers

with their ports in the WebLogicCluster directive.

If you add or remove members to or from this list, you may

have to restart OHS.


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Starting and Stopping OHS Manually

To give effect to configuration changes to httpd.conf,

you should restart OHS.

The processing life cycle for OHS is managed by Oracle

Process Manager and Notification Server (OPMN).

The command-line interface to OPMN is opmnctl. To restart OHS, use the following command:

You can also stop, and then start OHS.

$> ./opmnctl restartproc process-type=OHS

$> ./opmnctl stopproc process-type=OHS

$> ./opmnctl startproc process-type=OHS


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Verifying Access Through OHS

Get the port on which OHS is running by using:

$>./opmnctl status lProcesses in Instance: wtinst

--------------+-------------+------+-------+-----------+-

---------+-----------+------------------------------

ias-component | process-type| pid |status | uid | memused | uptime | ports

--------------+-------------+------+-------+-----------+-

---------+-----------+------------------------------

ohsa | OHS | 8614 | Alive | 1775979054|

348736 | 0:00:29 | https:8889,https:4443,http:8888


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Quiz

Which of the following is NOT an available configuration

attribute associated with Oracle WebLogic Cluster?

1. Messaging mode

2. Multicast TTL

3. Multicast port

4. Broadcast server


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Summary

In this lesson, you should have learned how to:

Prepare your environment for a cluster

Create and configure a cluster

Add servers to a cluster

Start up and shut down clustered servers


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Practice 16 Overview:

Configuring Clusters

This practice covers the following topics:

Creating a cluster

Assigning two servers to the cluster

Verifying the port and status of Oracle HTTP Server


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Les 16-Configure Cluster